5.1. Booting the Installer on Alpha

5.1.1. Alpha Console Firmware

Console firmware is stored in a flash ROM and started when an Alpha
system is powered up or reset. There are two different console
specifications used on Alpha systems, and hence two classes of console
firmware available:

SRM console, based on the Alpha Console Subsystem
specification, which provides an operating environment for OpenVMS, Tru64
UNIX, and Linux operating systems.

ARC, AlphaBIOS, or ARCSBIOS console, based on the
Advanced RISC Computing (ARC) specification, which provides an operating
environment for Windows NT.

From the user's perspective, the most important difference between SRM
and ARC is that the choice of console constrains the possible
disk-partitioning scheme for the hard disk which you wish to boot off
of.

ARC requires that you use an MS-DOS partition table (as created by
cfdisk) for the boot disk. Therefore MS-DOS partition
tables are the “native” partition format when booting from
ARC. In fact, since AlphaBIOS contains a disk partitioning utility, you may
prefer to partition your disks from the firmware menus before
installing Linux.

Conversely, SRM is incompatible[4] with MS-DOS partition tables. Since Tru64 Unix uses the BSD
disklabel format, this is the “native” partition format for
SRM installations.

GNU/Linux is the only operating system on Alpha that can be booted from
both console types, but Debian GNU/Linux 4.0 only supports booting on
SRM-based systems. If you have an Alpha for which no version of SRM is
available, if you will be dual-booting the system with Windows NT, or if
your boot device requires ARC console support for BIOS initialization,
you will not be able to use the Debian GNU/Linux 4.0 installer. You can
still run Debian GNU/Linux 4.0 on such systems by using other install
media; for instance, you can install Debian woody with MILO and upgrade.

Because MILO is not available for any of the Alpha
systems currently in production (as of February 2000), and because it
is no longer necessary to buy an OpenVMS or Tru64 Unix license to have
SRM firmware on your older Alpha, it is recommended that you use SRM
when possible.

Generally, none of these consoles can boot Linux directly, so the
assistance of an intermediary bootloader is required. For the SRM
console, aboot, a small, platform-independent
bootloader, is used. See the (unfortunately outdated) SRM HOWTO for more information on
aboot.

The majority of AlphaServers and all current server and workstation
products contain both SRM and AlphaBIOS in their firmware. For
“half-flash” machines such as the various evaluation boards,
it is possible to switch from one version to another by reflashing the
firmware. Also, once SRM is installed, it is possible to run
ARC/AlphaBIOS from a floppy disk (using the arc
command). For the reasons mentioned above, we recommend switching to
SRM before installing Debian GNU/Linux.

As on other architectures, you should install the newest available
revision of the firmware[5] before installing Debian GNU/Linux.
For Alpha, firmware updates can be obtained from
Alpha Firmware Updates.

5.1.2. Booting with TFTP

In SRM, Ethernet interfaces are named with the ewa
prefix, and will be listed in the output of the show dev command,
like this (edited slightly):

This will boot using the default kernel parameters as included in the
netboot image.

If you wish to use a serial console, you must
pass the console= parameter to the kernel.
This can be done using the -flags argument to
the SRM boot command. The serial ports are
named the same as their corresponding files in
/dev. Also, when specifying additional kernel
parameters, you must repeat certain default options that are needed by
the debian-installer images. For example, to boot from ewa0
and use a console on the first serial port, you would type:

>>> boot ewa0 -flags "root=/dev/ram ramdisk_size=16384 console=ttyS0"

5.1.3. Booting from CD-ROM with the SRM Console

The Debian GNU/Linux install CDs include several preconfigured boot options for
VGA and serial consoles. Type

>>> boot xxxx -flags 0

to boot using VGA console, where xxxx is your
CD-ROM drive in SRM notation. To use serial console on the first
serial device, type

>>> boot xxxx -flags 1

and for console on the second serial port, type

>>> boot xxxx -flags 2

[4]
Specifically, the bootsector format required by the Console Subsystem
Specification conflicts with the placement of the DOS partition table.